Although it is applicable to any desired components, the present invention as well as the problems on which it is based are explained here with respect to an automotive component.
To detect an accident or an impact involving a vehicle, sensors are conventionally installed in the vehicle. By analyzing the measurement results of these sensors, various vehicle occupant safety applications provided in the vehicle may be activated in case of need. Pressure sensors may be used in a part located on the side of the vehicle, e.g., a door of the vehicle for detecting a side impact.
German Patent No. 41 15 202 describes a method and a device for recognizing whether a seat in a vehicle is occupied by a person. A sensor is provided with which a container is filled with an incompressible free-flowing medium. The mass or volume of displaced medium can be detected by the sensor. German Patent Application No. 195 04 353 describes a deformation sensor which, when an internal pressure of a deformable box is detected by a pressure sensor, delivers an electric signal depending on the pressure thus detected.
With pressure sensors, certain types of interference may make reliable detection of an accident or crash highly difficult. For example, insufficient sealing in the door structure may cause additional pressure fluctuations which have a negative effect on the measurement accuracy of pressure sensors.
Likewise, in the event of an accident, there may be severe damage to the corresponding vehicle part in which the pressure sensor is installed, and thus inaccurate measurement results may be obtained or there may even be a system failure.
Slamming of a vehicle door or a trunk lid may cause a sudden pressure increase inside the vehicle, so that a faulty signal is delivered for deployment of a vehicle occupant safety application.
In addition, the pressure sensors detect only a limited area, and it is difficult to adapt them to the prevailing geometric design of the corresponding component.